I have a '48 Pacemaker Speed Graphic, the focal plane shutter (which is what I mostly use, I don't have the front leaf shutter trigger switch) seems to work fine, except when I hold the camera in a portrait position. Holding it that way makes my shutter lag on anything slower than 1/500. I have disassembled the side of the camera, exposing the gear for the top focal plane roller holding the cloth.

What would I have to adjust or clean to get the camera back in working shape? I don't see a main spring that tensions when the shutter is wound.

You download the factory service manual
http://www.graflex.org/manuals/45-Pacemaker-Speed-and-Crown-Graphic.pdf
then you disassemble the shutter, instructions start on manual page 6, pdf page 12. Clean the moving parts including the shaft bushings on the left side. The shaft bushings are under the leatherette covering on some early Pacemakers and outside the leatherette on others, either way they are threaded in and unscrew like standard right hand thread screws. the bushings wear to the shafts so keep their positions, top to top.
The tension spring is inside the lower roller, the roller ends unscrew from the main tube left side first. No need to disassemble it.

Tip, set the curtain to O then with the back removed mark the position of the top stay of the aperture on the case edge. This makes reassembly alignment easier._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

That long black rod is the lower tension roller shaft.
If the tension roller seal is not there it was either removed in previous servicing or was not used on your camera.
Whoever wrote these service manuals were not good at writing service manuals, details are left out or steps are out of sequence making it a lot of fun for non technical people and the inexperienced.

Take hold of the gear end of the tension roller shaft and pull it outward as far as it will go then hold in this position while lifting up on the left end of the tension roller until the center of the roller is clear of the case edge then release the shaft and continue lifting out the roller and shaft sliding it to the left.

EDIT:
If you are referring to the guide rollers blocking the curtain roller then with the curtain at O gently pull the curtain strips out of the way and remove the screws holding the guide roller frame to the case then slide the guide roller assembly from under the curtain._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

I seem to have broken the shaft following your instructions and the bottom roller is stuck halfway outside the camera. I can't pull it out and I cannot push it back in. I may have to cut through the curtain. I will wait for a reply first to see if anything can be done.

you have my email, send ma a picture or two.
I don't unserstand how you can jam the roller and need to cut the curtain._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.